example05.java

本体推理工具 共八个例子:从如何建立本体到做一些简单的的本体推理

package ex05;

import java.util.*;

import org.semanticweb.kaon2.api.*;
import org.semanticweb.kaon2.api.logic.*;
import org.semanticweb.kaon2.api.owl.elements.*;
import org.semanticweb.kaon2.api.reasoner.*;

/**
 * This example shows how to use KAON2 built-in predicates. Using these predicates one can evaluate arithmetic expression
 * or perform value comparisons.
 */
public class Example05 {
    public static void main(String[] args) throws Exception {
        // To create an ontology, we again start by creating a connection.
        // We again need to register a resolver that will provide a physical URI
        // for the ontology. In this example, the physical URI is relative to the current directory.
        KAON2Connection connection=KAON2Manager.newConnection();
        DefaultOntologyResolver resolver=new DefaultOntologyResolver();
        resolver.registerReplacement("http://kaon2.semanticweb.org/example05","file:example05.xml");
        connection.setOntologyResolver(resolver);

        // We create an ontology by specifying its logical URI. The resolver provides the physical URI.
        // Up until now this example is the same as Example 2.
        Ontology ontology=connection.createOntology("http://kaon2.semanticweb.org/example05",new HashMap<String,Object>());

        List<OntologyChangeEvent> changes=new ArrayList<OntologyChangeEvent>();

        // We now add some axioms to the ontology. In this example, we address the highly acute problem of people
        // beeing too fat, and provide means for classifying people according to their body-mass-index.
        // The information in this example is based on http://www.uni-hohenheim.de/~wwwin140/info/interaktives/bmi.htm
        // with some "artist's free interpretation".
        OWLClass person=KAON2Manager.factory().owlClass("http://kaon2.semanticweb.org/example05#person");

        // These are the classes into which people are classified according to their body-mass-index.
        OWLClass twig=KAON2Manager.factory().owlClass("http://kaon2.semanticweb.org/example05#twig");
        OWLClass normalWeight=KAON2Manager.factory().owlClass("http://kaon2.semanticweb.org/example05#normalWeight");
        OWLClass chubby=KAON2Manager.factory().owlClass("http://kaon2.semanticweb.org/example05#chubby");
        OWLClass walrus=KAON2Manager.factory().owlClass("http://kaon2.semanticweb.org/example05#walrus");
        OWLClass whale=KAON2Manager.factory().owlClass("http://kaon2.semanticweb.org/example05#whale");

        changes.add(new OntologyChangeEvent(KAON2Manager.factory().subClassOf(twig,person),OntologyChangeEvent.ChangeType.ADD));
        changes.add(new OntologyChangeEvent(KAON2Manager.factory().subClassOf(normalWeight,person),OntologyChangeEvent.ChangeType.ADD));
        changes.add(new OntologyChangeEvent(KAON2Manager.factory().subClassOf(chubby,person),OntologyChangeEvent.ChangeType.ADD));
        changes.add(new OntologyChangeEvent(KAON2Manager.factory().subClassOf(walrus,person),OntologyChangeEvent.ChangeType.ADD));
        changes.add(new OntologyChangeEvent(KAON2Manager.factory().subClassOf(whale,person),OntologyChangeEvent.ChangeType.ADD));

        // Data property 'height' contains the height of a person in centimeters.
        DataProperty height=KAON2Manager.factory().dataProperty("http://kaon2.semanticweb.org/example05#height");
        // Data property 'weight' contains the height of a person in kilograms.
        DataProperty weight=KAON2Manager.factory().dataProperty("http://kaon2.semanticweb.org/example05#weight");
        // Data property 'bmi' contains the body-mass-index of a person.
        DataProperty bmi=KAON2Manager.factory().dataProperty("http://kaon2.semanticweb.org/example05#bmi");

        // KAON2 currently does not support domain and range assertions for data properties. Hence, we shall NOT
        // state that the domain of 'height', 'weight' and 'bmi' is 'Person', and that the range is 'Integer';
        // doing so would currently prohibit answering any query. Similarly, we shall not state that these
        // properties are functional.  However, we still can use data properties in builtin predicates.
        Individual alice=KAON2Manager.factory().individual("http://kaon2.semanticweb.org/example05#alice");
        Individual bob=KAON2Manager.factory().individual("http://kaon2.semanticweb.org/example05#bob");
        Individual chuck=KAON2Manager.factory().individual("http://kaon2.semanticweb.org/example05#chuck");

        // The values of data properties can be arbitrary objects. For numeric values, KAON2 supports the usual conversions.

        // Alice is obsessed with her waistline, so she doesn't eat much...
        changes.add(new OntologyChangeEvent(KAON2Manager.factory().dataPropertyMember(height,alice,KAON2Manager.factory().constant(new Integer(160))),OntologyChangeEvent.ChangeType.ADD));
        changes.add(new OntologyChangeEvent(KAON2Manager.factory().dataPropertyMember(weight,alice,KAON2Manager.factory().constant(new Integer(40))),OntologyChangeEvent.ChangeType.ADD));

        // ...but therefore Bob cleans her fridge each time he vists her!
        changes.add(new OntologyChangeEvent(KAON2Manager.factory().dataPropertyMember(height,bob,KAON2Manager.factory().constant(new Double(180))),OntologyChangeEvent.ChangeType.ADD));
        changes.add(new OntologyChangeEvent(KAON2Manager.factory().dataPropertyMember(weight,bob,KAON2Manager.factory().constant(new Float(125.0))),OntologyChangeEvent.ChangeType.ADD));

        // Chuck likes to eat well on social occasions, but he exercises regularly and is very active in his running club.
        // Notice that we specify the weight of Chuck as a string. This is important for the discussion below about type conversions.
        changes.add(new OntologyChangeEvent(KAON2Manager.factory().dataPropertyMember(height,chuck,KAON2Manager.factory().constant(new Integer(184))),OntologyChangeEvent.ChangeType.ADD));
        changes.add(new OntologyChangeEvent(KAON2Manager.factory().dataPropertyMember(weight,chuck,KAON2Manager.factory().constant("74")),OntologyChangeEvent.ChangeType.ADD));

        // A formula can be evaluated using kaon2:evaluate(F,A1,...,An,R) predicate. The arguments have the following meaning:
        // - F is the string formula to evaluate
        // - Ai are the arguments
        // - R is the result of the evaluation
        //
        // You should think of the extension of this predicate as the set all all assertions of the above form where
        // evaluating F on the arguments Ai result in the result R.
        //
        // The formula F is a string which says what is to be evaluated. In the formuala one can use standard arithmetic
        // operators +, -, *, /, %, parenthesis, relational operators ==, !=, <, >, <=, >= and Boolean operators &&, || and !.
        // One can also use builtin functions, such as sum, sub, mul, div, min, max, concat, and, or, isuri, isliteral, regex and
        // conversion functions byte, short, int, long, float, double and str. The argument value Ai is denoted as $i (i should be
        // replaced with the actual number). Finally, one can use string constants delimited with "...", number constants
        // (interpreted as Double Java type), and arbitrary constants, whose syntax is "..."^^datatypeURI or "..."^^<datatypeURI>.
        //
        // We now create the rule that computes the body-mass-index, using the following formula:
        //
        //   BMI = WEIGHT / ((HEIGHT/100) * (HEIGHT/100))
        //
        // This can be accompished using the formula '$1/(($2/100.0)*($2/100.0))' (without apostrophes); this means that we
        // divide the value of the first argument with the square value of the second argument (converted into cm).
        // Hence, the literal in the rule has the form
        //
        //   kaon2:evaluate("$1/($2*$2)",WEIGHT,HEIGHT,BMI)
        //
        Variable HEIGHT=KAON2Manager.factory().variable("HEIGHT");
        Variable WEIGHT=KAON2Manager.factory().variable("WEIGHT");
        Variable BMI=KAON2Manager.factory().variable("BMI");
        Literal evaluateBMI=KAON2Manager.factory().literal(true,
            // The predicate is the kaon2:evaluate predicate, with the arity 4.
            KAON2Manager.factory().evaluate(4),
            new Term[] {
                KAON2Manager.factory().constant("$1/(($2/100.0)*($2/100.0))"),
                WEIGHT,
                HEIGHT,
                BMI
            });

        // To invoke the above literal, we need a rule which will match the values of HEIGHT and WEIGHT to some
        // concrete values. In general, only the last argument of kaon2:evaluate is allowed to be invoked free.
        Variable PERSON=KAON2Manager.factory().variable("PERSON");
        Rule computeBMI=KAON2Manager.factory().rule(
            KAON2Manager.factory().literal(true,bmi,new Term[] { PERSON,BMI }),
            new Literal[] {
                KAON2Manager.factory().literal(true,weight,new Term[] { PERSON,WEIGHT }),
                KAON2Manager.factory().literal(true,height,new Term[] { PERSON,HEIGHT }),
                evaluateBMI
            });